MOSCOW -- The Russian Federal Penitentiary Service (FSIN) has said doctors found no traces of trauma or assault on a jailed activist who alleges he was tortured.

Human rights activists, however, have expressed doubts over the independence of the prison service's findings.

Ildar Dadin made shocking allegations on November 1 in which he said he was subjected to violent beatings and threatened with murder by the warden and staff of the prison in the northwestern region of Karelia where he is serving a 2 1/2-year sentence.

But on November 2, The FSIN's press service said a group of "independent" doctors conducted a preliminary medical examination of Dadin, assessing his condition to be "satisfactory" and saying no signs of battery or earlier trauma were found on him.